The FAA’s proposal to increase the Detroit Class B airspace ceiling to 10,000 feet msl and expand much of the airspace from 25 nautical miles to 30 nm lacks justification, AOPA wrote in formal comments Aug. 23.

The agency has provided no data regarding safety or containment concerns that justify the expansion in these areas. The FAA asserted that raising the ceiling from 8,000 feet msl to 10,000 feet msl was an attempt to standardize the Detroit airspace with other Class B airspace. AOPA pointed out that only 56 percent of Class B airspace has a ceiling of10,000 feet msl or above and that some of the busiest Class B areas in the country have ceilings below 10,000 feet msl.

“AOPA is concerned that the FAA is enlarging the Class B airspace to contain aircraft receiving radar vectors from air traffic control, when the charted instrument approach procedure is fully contained within the existing Class B airspace,” wrote AOPA Manager of Air Traffic Services Tom Kramer. Although Class B airspace is designed to contain instrument approaches, AOPA notes that if radar vectors routinely take aircraft outside the limits of the airspace, the procedures for radar vectors should be reviewed, instead of expanding the airspace.

“If it is determined through revised procedures that the 25- to 30-nm ring is required, AOPA requests that the FAA raise the floor from 6,000 feet to 8,000 feet throughout the outermost ring,” AOPA said.

In its comments, the association also criticized the FAA for failing to follow established requirements to provide details about the airspace proposal in advance of informal airspace meetings. Failing to do so limited the amount of time airspace users had to review the plan and ask questions at the meeting.